The 11 challengers to be D.A. created the hottest race in the county, with the large field and substantial discontent with Gascón all but certain to prevent anyone from winning a majority, setting up an expected November runoff between the two top finishers.

Tuesday’s election also put nearly half the seats on the Los Angeles City Council and the majority of the five-member county Board of Supervisors before voters, along with the question of who will replace two venerable L.A. school board members and a ballot measure intended to substantially rework traffic patterns in the city of Los Angeles.

Citizen-sponsored Measure HLA would take road projects that have languished for years on drawing boards and push them toward reality — adding more than 600 miles of bicycle lanes and 200 miles of bus lanes around the city.

Among the many projects the measure identifies are protected bike lanes on Sunset and Venice boulevards, and a bus lane connecting Whittier Boulevard in Boyle Heights to 6th Street downtown, then to Wilshire Boulevard west of the 110 Freeway.

Approval of HLA would effectively fast-forward the city’s ambitious Mobility Plan, which calls for special improvements every time the city repaves an eighth of a mile, or more, of street. Though some of the plans would constrict car traffic, they also identify about 80 miles of road where efficient vehicle travel would be the priority.

HLA’s backers say it will promote multiple forms of transportation and make streets safer by slowing cars down. Opponents contend the measure will create unintended danger, by slowing emergency vehicles. The cost of implementing the proposal also has created a sharp split: with the city’s top budget official saying it will have a price tag of at least $3.1 billion, while proponents say it will cost much less.

Perhaps the most closely watched of the seven Los Angeles City Council contests has been the reelection bid of Nithya Raman, a progressive whose election four years ago helped usher in an increased interest at City Hall in renters’ rights and crime-reduction tactics not solely reliant on police.

Raman has had to focus on more than policy during her first term. She fought off a recall attempt that never reached the ballot and now faces a bid for a second term in a district whose boundaries were substantially redrawn in a way that cut the number of generally liberal-leaning renters. Cut from the 4th District: tenant-heavy areas such as Park La Brea. Added: single-family home havens such as Encino, and parts of Studio City and Reseda.

In the most expensive council race this year, Deputy City Atty. Ethan Weaver has positioned himself as a moderate alternative.

Raman has drawn a clear distinction with Weaver and some of her current colleagues by opposing a city law that prohibits homeless encampments near schools. The councilwoman also voted against a package of pay raises for the LAPD. Weaver supports the police raises, along with the law limiting the location of homeless encampments.

The city councilwoman, who lives in Silver Lake, had the distinction in 2020 of becoming the first member of the Democratic Socialists of America to oust an incumbent at City Hall. The leftward tilt at City Hall proved much more than an anomaly two years later when three other candidates won with substantial help from DSA volunteers — now incumbent council members Hugo Soto-Martínez and Eunisses Hernandez and City Controller Kenneth Mejia.

Weaver has sought to portray the DSA as too “radical” for the district. Raman has countered that she is a “pragmatic progressive.” Her vote for Mayor Karen Bass’ budget, which called for hiring 1,000 police officers, did not sit well with some on the left.

Another high-profile L.A. city contest puts Councilmember Kevin de León in front of voters for the first time since a secret recording caught him, two other council members and a labor leader engaged in an inflammatory and racist discussion of how to carve up political districts in L.A.

The October 2021 recording, which was leaked a year later, spurred multiple calls for De León to resign, but he has held his post representing the 14th District, which includes northeast Los Angeles. Among the seven candidates competing to replace him are two former members of the state Assembly, a DSA-backed activist, a high school science teacher, a real estate attorney, a geriatric social worker and a nonprofit consultant.

In Los Angeles County, three incumbents are running for reelection to the Board of Supervisors.

After serving in the state Senate and one term on the county board, Holly Mitchell is the establishment candidate in the 2nd District. The incumbent touts endorsements from Bass, labor unions and the Sierra Club.

The county’s 4th District is home to Supervisor Janice Hahn, part of a political dynasty headlined for four decades by her father, Supervisor Kenneth Hahn, and also including her brother, a former city controller, city attorney and mayor.

Hahn has drawn a well-known and controversial opponent, former Sheriff Alex Villanueva, who bridled at oversight of his department and lost his reelection bid in a landslide in 2022. The two are joined on the ballot by John Cruikshank, who has served seven years as a council member and mayor in Rancho Palos Verdes.

The 5th supervisorial district, which reaches to the north end of the county, has been represented since 2016 by Kathryn Barger. Although she is a Republican, Barger has won the backing of labor unions, including SEIU Local 721 and the Assn. for Los Angeles Deputy Sheriffs, which represents rank-and-file members of the Sheriff’s Department. She also has the endorsement of a Planned Parenthood advocacy group.

The challenger with the highest political profile is Chris Holden, a Democrat who represents Pasadena in the state Assembly and who is forced by term limits to leave that post. Holden also has substantial labor backing, including from a pair of SEIU locals.

The Los Angeles Board of Education will be reshaped by Tuesday’s election as two significant political and education figures — Jackie Goldberg and George McKenna — will retire at the end of the year. In all, 18 candidates are vying to hold one of four seats on the ballot. Most races are likely to be settled with a runoff in November.

The outcome will determine whether the board majority will be more or less supportive of charters, which are privately managed, mostly nonunion public schools. The district faces financial uncertainty due to declining enrollment and the expiration of pandemic-relief aid, as it attempts to boost student achievement.

Times staff writer Howard Blume contributed to this report.